Fuel effiency
11-Feb-2009, 02:43 AM
#1
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Join Date: Feb 2009
Location: Mississauga
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Fuel effiency
Hey all,
I was just wondering what kind of modifications or additions I can do to my car to make it more fuel efficient. Would adding stuff like intake or a new exhaust system make my car more fuel efficient? Any input would be appreciated. It's stock to the bone right now.
I was just wondering what kind of modifications or additions I can do to my car to make it more fuel efficient. Would adding stuff like intake or a new exhaust system make my car more fuel efficient? Any input would be appreciated. It's stock to the bone right now.
11-Feb-2009, 07:41 AM
#3
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to make it more fuel efficient gut the interior. more weight=more gas=less power
make sure your tire pressure is correct since that affects how far you can roll. also a good tune up to make sure plugs are gapped wires are good, distributor cap and rotor are working properly. if one of those components is not, you will use more gas than you should be.
make sure your tire pressure is correct since that affects how far you can roll. also a good tune up to make sure plugs are gapped wires are good, distributor cap and rotor are working properly. if one of those components is not, you will use more gas than you should be.
11-Feb-2009, 11:01 AM
#4
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to make it more fuel efficient gut the interior. more weight=more gas=less power
make sure your tire pressure is correct since that affects how far you can roll. also a good tune up to make sure plugs are gapped wires are good, distributor cap and rotor are working properly. if one of those components is not, you will use more gas than you should be.
make sure your tire pressure is correct since that affects how far you can roll. also a good tune up to make sure plugs are gapped wires are good, distributor cap and rotor are working properly. if one of those components is not, you will use more gas than you should be.
Plugs, wires, cap/rotor, change all the fluids (oil, tranny, coolent), adjust worn tires and set the correct pressure, get an alignment and most importanly, change your driving habits. Accelerate slowly and smoothly, shift at a normal rpm, dont drive so fast on the highway.
11-Feb-2009, 11:42 PM
#5
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Letting more air in/out of the engine will most likely hurt your fuel mileage because #1 your gonna drive more aggressively because now your car sounds faster and sounds like it has a couple more ponies, #2 the more air that enters the engine the more fuel it will inject to maintain the proper air/fuel ratio. More air in/out = more fuel.
However, opening up the intake and exhaust can help the engine more efficiently suck in and blow out the air/burnt gasses, which is easier on the engine and therefore you would not have to use as much throttle to maintain a certain speed on the road. But the difference is negledgable.
The things that will really make a difference is vehicle weight and aerodynamics. Slam the car, make up some flat panels that cover the entire bottom of the car, especially the rear bumper which acts like a giant inverted scoop. Also, cover any openings that are not functional on the front of the car.
There are many things you can do but the most difference can be made by your driving style. Shift at an rpm where your engine is operating in it's efficiency range. Not screaming and not ******* down low. Use minimal throttle to accelerate, your not racing. I usually shift between 2500 and 3500 with my B16 and that gives me enough juice to get up to speed without flooring it and people aren't honking at me because I'm going to slow. If your car is standard then you're at an advantage. Fuel injected engines DO NOT burn a drop a fuel when the engine is decellerating (untill about 2000 rpm). This means when your slowing or coasting down hill, leave the engine in gear and just let the engine slow the car. You're not burning any fuel during this time. Many people think if they put the car in neutral and let it idle while going down hill or braking they are saving fuel, the truth is they're burning MORE fuel. By down-shifting and letting the engine decellerate the car, you're not burning ANY fuel!
Don't drive like a crazy man, lower the car, and up your tire pressure. Those are the most basic things you can do without making drastic mods to the car.
However, opening up the intake and exhaust can help the engine more efficiently suck in and blow out the air/burnt gasses, which is easier on the engine and therefore you would not have to use as much throttle to maintain a certain speed on the road. But the difference is negledgable.
The things that will really make a difference is vehicle weight and aerodynamics. Slam the car, make up some flat panels that cover the entire bottom of the car, especially the rear bumper which acts like a giant inverted scoop. Also, cover any openings that are not functional on the front of the car.
There are many things you can do but the most difference can be made by your driving style. Shift at an rpm where your engine is operating in it's efficiency range. Not screaming and not ******* down low. Use minimal throttle to accelerate, your not racing. I usually shift between 2500 and 3500 with my B16 and that gives me enough juice to get up to speed without flooring it and people aren't honking at me because I'm going to slow. If your car is standard then you're at an advantage. Fuel injected engines DO NOT burn a drop a fuel when the engine is decellerating (untill about 2000 rpm). This means when your slowing or coasting down hill, leave the engine in gear and just let the engine slow the car. You're not burning any fuel during this time. Many people think if they put the car in neutral and let it idle while going down hill or braking they are saving fuel, the truth is they're burning MORE fuel. By down-shifting and letting the engine decellerate the car, you're not burning ANY fuel!
Don't drive like a crazy man, lower the car, and up your tire pressure. Those are the most basic things you can do without making drastic mods to the car.
12-Feb-2009, 01:02 AM
#7
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Join Date: Feb 2008
Posts: 494
Hey all,
I was just wondering what kind of modifications or additions I can do to my car to make it more fuel efficient. Would adding stuff like intake or a new exhaust system make my car more fuel efficient? Any input would be appreciated. It's stock to the bone right now.
I was just wondering what kind of modifications or additions I can do to my car to make it more fuel efficient. Would adding stuff like intake or a new exhaust system make my car more fuel efficient? Any input would be appreciated. It's stock to the bone right now.
The very first thing you want to "modify" is your tire pressures. Run them at the highest pressure indicated on the tire sidewall to reduce rolling resistance and check tires pressures often. Most people tend to overlook their tire pressures, and fuel economy drops by about 1% or more for every 2 psi drop in tire pressure.
By "bone stock", I'm going to assume that your tires are already at stock size. If not, be aware that wider low profile performance tires typically create 50 to 100% more rolling resistance than all season tires with a 70 or 75 series aspect ratio. This affects fuel economy - every 10% reduction in rolling resistance translates into 1 to 2% decrease in fuel consumption.
Other than performing basic tune-ups every now and then, you are unlikely to see enough fuel savings to recover the cost of even the most cheapest intake or exhaust modifications.
Last edited by FiveO; 12-Feb-2009 at 01:05 AM.
12-Feb-2009, 01:59 AM
#8
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....If not, be aware that wider low profile performance tires typically create 50 to 100% more rolling resistance than all season tires with a 70 or 75 series aspect ratio. This affects fuel economy - every 10% reduction in rolling resistance translates into 1 to 2% decrease in fuel consumption.
Performance tires do not create 50 to 100% more rolling resistance than all seasons. It depends on the diameter, width, compound and pressure. Yes a wider tire will have theoretically more rolling resistance, but not 50 to 100% more. Also if the wider tire has a harder rubber compound and you run it at a higher pressure, it can have a lower rolling resistance than a skinnier all season tire at a lower pressure. You can't just say a certain tire has a higher rolling resistance than another, there is a lot more to it than that.
Throw on some tires from a prius or civic hybrid. They have tires with much lower rolling resistance. That should help your fuel mileage. But you won't have any grip...lol.
12-Feb-2009, 04:18 AM
#9
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The profile of the tire has nothing to do with rolling resistance. What does effect rolling resistance is the overall diameter, the width of the tire and the rubber compound.
Performance tires do not create 50 to 100% more rolling resistance than all seasons. It depends on the diameter, width, compound and pressure. Yes a wider tire will have theoretically more rolling resistance, but not 50 to 100% more. Also if the wider tire has a harder rubber compound and you run it at a higher pressure, it can have a lower rolling resistance than a skinnier all season tire at a lower pressure. You can't just say a certain tire has a higher rolling resistance than another, there is a lot more to it than that.
Throw on some tires from a prius or civic hybrid. They have tires with much lower rolling resistance. That should help your fuel mileage. But you won't have any grip...lol.
Performance tires do not create 50 to 100% more rolling resistance than all seasons. It depends on the diameter, width, compound and pressure. Yes a wider tire will have theoretically more rolling resistance, but not 50 to 100% more. Also if the wider tire has a harder rubber compound and you run it at a higher pressure, it can have a lower rolling resistance than a skinnier all season tire at a lower pressure. You can't just say a certain tire has a higher rolling resistance than another, there is a lot more to it than that.
Throw on some tires from a prius or civic hybrid. They have tires with much lower rolling resistance. That should help your fuel mileage. But you won't have any grip...lol.
Many people go to low profile performance tires specifically to get more width for a given outer circumference. That extra width does translate into greater rolling resistance for a tire of a given circumference. The difference in rolling resistance becomes even more exaggerated on poor asphalt road surfaces, dirt, gravel, mud, or in rain or snow conditions.
There's a Transportation Research Board publication with a fair bit of technical content at http://www.google.ca/url?sa=t&source...4zem4EXITt-ELw .
"One of the OEMs indicated that the following new-tire rolling resistance
values are typical for four general categories of OE passenger tires:
• All-season, 0.007;
• Touring, 0.008;
• Performance, 0.01; and
• Light truck passenger, 0.0075 to 0.0095.
Another OEM provided the following new-tire rolling resistance ranges
for similar tire categories, which were derived by using the SAE
J2452 test procedure and reported by using the Standard Mean Equivalent
Rolling Force conditions described in the Appendix:
• All-season, 0.005 to 0.0062;
• Touring, 0.0058 to 0.0075;
• Performance, 0.0065 to 0.0083; and
• High performance, 0.009."
12-Feb-2009, 10:20 AM
#11
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12-Feb-2009, 11:57 AM
#12
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Many people go to low profile performance tires specifically to get more width for a given outer circumference. That extra width does translate into greater rolling resistance for a tire of a given circumference. The difference in rolling resistance becomes even more exaggerated on poor asphalt road surfaces, dirt, gravel, mud, or in rain or snow conditions.
People will go to a wider tire for a larger contact patch and in order to keep the diameter the same, you must go to a lower profile as a result.
Like going from 185/55R15 to 205/50R15.
Same thing just a different way of explaining it.
24-Feb-2009, 12:37 PM
#15
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24-Feb-2009, 09:18 PM
#17
500km is damn decent if you're doing a lot of city driving, especially in winter. Your tank is only 44 liters if I recall, and 500km/tank is on par with the 'advertised' city EPA rating for an Si.
Tuning it up isn't going to get you any more economy if there's nothing wrong to begin with.
Tuning it up isn't going to get you any more economy if there's nothing wrong to begin with.
25-Feb-2009, 12:12 PM
#18
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I do mostly hwy driving. I go to school in hamilton and live in sauga and I commute there almost everyday. Do you guys use 5th gear in the city? Like driving at 70-80 km/h. would you guys put it on 5th or keep it on 4th?
25-Feb-2009, 06:41 PM
#19
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Unless your doing a steady 30kph or less, ALWAYS put it in 5th. If you need to accelerate, down shift ot 2nd or 3rd.
You can actually use 5th all the way down to just above idle speed and it should be fine for a steady pace. It's when your going so slow that it would be below idle in 5th or you need to accelerate that you would need a lower gear.
